Updated April 14 2025:
Bell removed bridge mode from the Giga Hub around April 2024 for consumers. If you place your router on the WAN port of the GH you will experience double NAT which will prevent some more advanced services from running.
Bell does not support “Bridge Mode” but does support both PPPoE and DMZ.
I have prepared the following PDF to assist in configuration of the UDM and Bell Giga Hub using PPPoE or DMZ. One may be faster than the other depeding on your hardware: Giga Hub to 3rd Party Routers such as Ubiquiti UniFi